Exceptional Points in Open Quantum System Dynamics
Prof. Weijian Chen
Department of Physics
NCSU
Open systems with loss or gain, described by effective non-Hermitian Hamiltonians, have attracted significant attention over the last two decades. These systems generally possess complex eigenvalues and non-orthogonal eigenstates. Their degeneracies are known as exceptional points (EPs), where both the eigenvalues and the corresponding eigenstates are degenerate. This peculiar behavior has led to many non-intuitive phenomena and applications in classical platforms, such as EP sensors and chiral state transfer via encircling an EP. As interest in harnessing non-Hermiticities and EPs for quantum applications continues to grow, open quantum systems provide a natural platform to explore the relevant physics. In this talk, I will first discuss the realization of EPs in a circuit QED setup using dissipation engineering. Then, I will present experiments on chiral state transfer via dynamically encircling an EP and the approach to mitigate decoherence effects. Finally, I will discuss EPs in composite quantum systems, which offer a novel method for forming higher-order EPs. Our theory shows EP-induced disentanglement and accelerated entanglement generation in proximity to EPs.
Hosted by Prof. Jin